Liogenys isotarsis Cherman, 2021

Cherman, Mariana Alejandra, Basílio, Daniel Silva, Mise, Kleber Makoto, Frisch, Johannes & Almeida, Lúcia Massutti De, 2021, Liogenys Guérin-Méneville, 1831 (Coleoptera: Scarabaeidae: Melolonthinae Diplotaxini) from the Chacoan Province and its boundaries: taxonomic overview with four new species, Zootaxa 4938 (1), pp. 1-59 : 21-23

Liogenys isotarsis Cherman , new species

Figs. 9 ; 27 .

http://zoobank.org/ 0D51DD77-5048-4285-B0F6-A0785885A6F0

Type material: Holotype labeled ( USNM): [white typeset] “ Trinidad, Bolivia / 1922-23 / M. S. Pennington ”, [red, typeset and handwritten] “ LIOGENYS ISOTARSIS / HOLOTYPE / Cherman M. A.”, genitalia mounted.

Holotype deposited at USNM.

Diagnosis. Body elongate; purplish brown, pronotum and elytra coarsely punctate ( Fig. 9A ); clypeal emargination angulate, teeth very short; outer sides of clypeal teeth subparallel; pronotal posterior corners rounded ( Fig. 9B ); in males metatibia not carinate along the inner margin, apical inner surface glabrous; tarsomeres almost equal in width, cylindrical ( Fig. 9 D–E); pygidium flat, glabrous ( Fig. 9C ); parameres narrowed at the midline; widened towards the apex, apex equal in width to the basal portion ( Fig. 9F ); parameres convex in lateral view ( Fig. 9G ).

Holotype. Male. Length: 9.1 mm; width: 5.1 mm. Purplish brown. Head: distance between eyes more than three times the width of one eye; clypeal emargination deep, angulate and wide; teeth short, outer sides of anterior teeth subparallel; outer margin of anterior teeth noticeably shorter than the eye length; lateral margin slightly convex, not produced; distal maxillary palpomere, maximum width more than twice the apical width; fovea shallow, extending past the transverse midline; antenna with 10 antennomeres, club lighter in color and longer than the funicle. Thorax: anterior margin of pronotum slightly produced medially; pronotal disc glabrous, punctures strongly coarse and very sparse; posterior corners rounded; hypomere with short bristles, mesepisternum and sides of metaventrite with sparse thick bristles; distance between mesocoxae and metacoxae up to twice the length of the metacoxa; scutellum ogival, with two longitudinal rows of punctures strongly coarse. Elytra: shiny, glabrous, unicolored with the pronotum, coarsely punctate; elytral suture unicolored with the elytron and weakly elevated; ridges I, II, and IV more defined than ridge III. Legs: three protibial teeth, the middle and apical equal in size; the three teeth equally spaced; mesofemural surface almost glabrous, setae on margins; mesotibia cylindrical in cross section, surface coarsely sculptured; two transverse carinae, the apical carina complete; metacoxa with sparse bristles, more abundant near the insertion of the metafemur; basal apophysis of metacoxa produced; metatibia not carinate along the inner margin, apical inner surface glabrous; two metatibial transverse carinae present posteriorly; metatibial apical spurs of different lengths; the larger equal in length to the diameter of the tibial apex; protarsomeres and mesotarsomeres I to IV almost equal in width to the metatarsomeres I to IV ( Fig. 9E ); metatarsomere I equal in size to metatarsomere II; claw bifid, symmetrical, superior tooth of a claw longer and equal in width to the inferior, distance between teeth slightly longer than the inferior tooth. Abdomen: ventrites with scattered short bristles; propygidium slightly visible, glabrous; pygidium flat, subtrapezoidal, wide; pygidial width not exceeding distance between spiracles of propygidium; pygidial disc glabrous; pygidial apex rounded. Parameres: narrowed at the midline; basal region wider than the parameres combined at the transverse midline, parameral split at 2/3; inner margins slightly convergent, after the midline widened towards the apex, apex equal in width to the basal portion; parameres convex in lateral view.

Etymology. Adjective in the nominative singular. From Ancient Greek ἴΣΟΣ (ísos, “equal”) + tarsus. In Liogenys isotarsis all the three pairs of tarsi have almost the same width, even being a male.

Type locality. BOLIVIA, Trinidad [14°49’55.6’’S 64°54’09.6’’W] .

Geographical distribution. BOLIVIA (Beni).

Remarks. Liogenys isotarsis resembles L. unicolor Evans, 2003 ( Cherman et al. 2017, 2019a) in the size and body color. Liogenys isotarsis differs from L. unicolor mainly in the outer sides of clypeal teeth subparallel (follow the lateral margin of clypeus); the pronotum wider; the punctures of scutellum and elytra coarser; the elytral ridges more defined; and in the pygidium flat (convex). In males, the protarsomeres are even more cylindrical and less enlarged than in L. unicolor . The parameres resemble those of L. angustitarsis Cherman, 2019 ( Cherman et al. 2019a), but they differ mainly in the lateral view, which are concave in the new species. Females remain unknown.

Liogenys isotarsis is possibly associated only to Bolivian Chiquitano Forests, and might occur in sympatry with L. parallela Frey, 1965 and L. mendozana Moser, 1918 in their northernmost distribution.

Figures

FIGURE 9. Liogenys isotarsis Cherman, new species, male holotype views: A) dorsal, B) head and pronotum, C) pygidium, D) lateral, E) metatibia and tarsi, black rows indicate not enlarged tarsi of all legs, and parameres in views: F) dorsal, and G) lateral.

FIGURE 27. Geographical distribution of the Liogenys new species. Shaped points: new species; colors: Neotropical provinces (Morrone 2014) and Monte province from the South American Transition Zone (Roig-Juñent et al. 2018).